Known as a conventional technique of this kind is a laser processing method in which a wafer-like object to be processed is irradiated with laser light while locating a light-converging point within the object, so as to form a plurality of rows of modified regions within the object along a line to cut, and use the modified regions as start points for cutting (see, for example, Patent Document 1).    [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-205180